A chemically modified carbon paste electrode with 2-chlorobenzoyl ferrocene (2CBF) and carbon nanotube (2CBFCNPE) was employed to study the electrocatalytic oxidation of ascorbic acid in aqueous solution using cyclic voltammetry, square wave voltammetry and chronoamperometry. The diffusion coefficient (D = 1.42 × 10-6 cm2 s-1), and the kinetic parameter such as ...

Determination of Dopamine electrochemically by direct oxidation is difficult due to the co-oxidation of ascorbic acid present in high concentration in biological fluids in the same potential window. In this report, we present a non oxidative approach to electrochemically detect dopamine with high selectivity and sensitivity using our newly developed poly (anilineboronic acid ) composite with si...

A carbon-paste electrode spiked with 1-[4-(ferrocenyl ethynyl)phenyl]-1-ethanone was constructed by the incorporation of 1-[4-(ferrocenyl ethynyl)phenyl]-1-ethanone in a graphite powder silicon oil matrix. It shown by cyclic voltammetry and double potential-step chronoamperometry, which this ferrocene derivative modified a carbon-paste electrode, can catalyze the ascorbic acid oxidation in an a...

A method for the determination of ascorbic acid in vitamin C tablets based on a very simple paptode design on TLC strips is described. This procedure is based on the reduction of iron(III) with ascorbic acid and the formation of a colorful red complex with immobilized 2,2'-dipyridyl (dipy) on TLC strips. The linear range of the system was 20-200 ppm with a detection limit of 1 ppm and a relativ...

required for the prevention of deficiency diseases such as scurvy, it also might be useful for reducing the risk of developing chronic diseases such as cancer, cardiovascular disorders, and cataracts. The protective mechanism probably is due to the antioxidant effect of ascorbic acid (10). Therefore, applications of various detection systems and analytical procedures for the separation of ascor...

in this work, an optical sensor for detection of ascorbic acid is described. the sensor is fabricated by casting and spin-coating silica sol-gel doped with 2,6-dichlorophenol indophenol on the glass plates. the sols are in turn obtained by acidic hydrolysis of various precursors such as tetraethoxysilane, triethoxymethylsilane and triethoxyoctylsilane in the presence of 2,6-dichlorophenol indop...

BACKGROUND Ascorbic acid is one of the most important vitamins to monitor in dietary sources (juices and vitamins) and biological liquids. RESULTS Silica and silica-titania xerogels doped with Mo,P-heteropoly compounds (HPC) have been synthesized varying titanium(IV) and HPC content in sol. Their surface area and porosity have been studied with nitrogen adsorption and scanning electron micros...

Voltammetric techniques have been considered as important methods among the analytical techniques used for the identification and determination of trace concentrations of many biological molecules such as L-ascorbic acid (AA). L-ascorbic acid is an electro-active molecule, though it is difficult to determine its value directly with a majority of electrodes made of carbon and transition metals, ...

Voltammetric techniques have been considered as important methods among the analytical techniques used for the identification and determination of trace concentrations of many biological molecules such as L-ascorbic acid (AA). L-ascorbic acid is an electro-active molecule, though it is difficult to determine its value directly with a majority of electrodes made of carbon and transition metals, ...

A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid c...